1. 1 Updates from MetaSUB Beijing Chu Ping Beijing Children’s Hospital Beijing Key Laboratory for Pediatric Diseases of Otolaryngology, Head and Neck Surgery

2. 2 Content Brief Introduction of Beijing Subway Pilot Study

3. 3 Brief Introduction of Beijing Subway The Beijing Subway has 18 lines, 334 stations and 554 km of track in operation, and is the second longest subway system in the world after the Shanghai Metro. The subway is the world's busiest in annual ridership, with 3.41 billion trips delivered in 2014, averaging 9.2786 million per day, with peak single-day ridership reaching 11.5595 million.

4. 4 Lines Beijing Subway lines generally follow the checkerboard layout of the city. Most lines through the urban core (outlined by the Line 10 loop) run parallel or perpendicular to each other and intersect at right angles. Most lines through the urban core run parallel or perpendicular to each other and intersect at right angles. Of the 18 lines, 12 are numbered and the other six are named after destinations in the outer suburbs.

5. 5 History 1953–1965: origins – The Beijing Subway opened in 1969 and is the oldest metro system in mainland China. The subway has undergone rapid expansion since 2002, as only two lines were in service before then.

6. 6 History 1965–1981: the slow beginning 1981–2000: two lines for two decades 2001–2008: planning for the Olympics 2008–present: rapid expansion – After the Chinese government announced a ¥4 trillion economic stimulus package in November 2008, the Beijing urban planning commission further expedited subway building plans, especially for surface light rail to suburban districts that are cheaper to build.

7. 7 Content Brief Introduction of Beijing Subway Pilot Study

8. 8 Sampling Position Nanlishilu Dawanglu Yonghegong

9. 9 The sampling process Sampling point location – Handrail of elevators – Bench Swab the entire surface for 3 minutes 4 replicates per station

10. 10 Experimental Design DNA purification – MoBio DNA Extraction Kit Library preparation – Nextera XT 96 Kit Sequencing – Illumina X10 Sequencer, 150PE, 60M reads/sample Data mining – Diamond Blasting and Megan LCA Analysis Sampling DNA Extraction Library Prep DNA Seq Data Mining

11. 11 Thank you